This invention relates to a sheet feeding apparatus and reproducing machine using that apparatus wherein a friction retard separating and feeding means is employed.
A great variety of friction retard type feeders have been utilized in the prior art. One particularly unique design for a friction retard separator which has proved to be a highly reliable means for feeding individual sheets one at a time from a stack is described in U.S. Pat. No. 3,768,803 assigned to the assignee of the instant invention. In the disclosed separator a feed belt is supported for movement about a pair of pulleys. A curved retard means is positioned against the unsupported section of the belt between the pulleys to form a sheet queing throat or nip. The belt contacts the stack near the edge and the throat acts to que or align the sheets for advancement into the sheet handling system. In this approach only the top most sheet is fed through the separator, however, adjacent sheets are shingled in the throat formed between the belt and the retard pad. A given level of nip force is exerted between the retard means and the feed means in order to obtain proper sheet separation.
If one desires to clear a jam in the paper feeder or to change sheet stacks it is generally necessary to also remove one or more sheets which are shingled in the nip of the separator feeder. This is a problem common to most friction retard type separators.
2,635,874 APPROACH TO SOLVING THIS PROBLEM IS ILLUSTRATED IN U.S. Pat. No. 2,635,974 wherein a retard roll is mounted to be pivoted away from engagement with the feeder. In U.S. application Ser. No. 398,024, filed Sept. 17, 1973, now U.S. Pat. No. 3,883,133, and assigned to the assignee of the instant invention. A roll type friction retard separator is provided wherein the retard roll can be pivoted away from the feed roll by the operator in order to clear jammed or shingled sheets. In U.S. Pat. application Ser. No. 342,653, filed Mar. 19, 1973, and assigned to the assignee of the instant invention, a retard pad and belt feeder are provided wherein the pad may be pivoted out of position to facilitate unloading of the stack support tray.
Each of these approaches require operator involvement to separate the nip of the separator for clearing a sheet shingled therein. In a compact environment such as might be found with a desk type copier there may not be sufficient room to allow access by the operator for the purpose of pivoting the retard means away from the feeder.